1. Field of the Invention
This invention relates generally to phased array antenna systems, and more particularly, to a phased array antenna which includes a light plane assembly for optically coupling the control system of the antenna with the individual phase control modules forming the antenna array.
2. Background Information
Both the construction and operation of conventional phased array antennas are well known. Phased array antennas presently in operation normally include a plurality of individual phase control module and radiator assemblies which are mounted to a printed wiring board positioned in the antenna housing. Electrical connections (e.g., for power/ground, beam update data, row/column data) between the antenna control system and the individual modules and radiator assemblies mounted to the printed wiring board are made through either a pin/socket or terminal/jumper wire arrangement at the interface between the printed wiring board and the phase control modules. If a pin/socket arrangement is utilized, the pins are connected with each module, and the sockets are assembled to a printed wiring board having typically 14 or 15 separate electrically conductive layers therein that essentially extends over the entire area of the array. Each socket is connected with an individual electrically conductive layer, and electrical information provided from the antenna control system is passed through the conductive layers and sockets to the individual module pins inserted in the sockets. If a terminal/jumper wire arrangement is utilized, terminals are mounted on the printed wiring board and are connected with selected electrically conductive layers embedded in the board. Jumper wires extending between the wiring board terminals and terminals mounted to an individual module are utilized to provide an electrical information transmission path between the antenna control system and the module.
It is readily apparent that the printed wiring board presently utilized to provide an electrical information transmission path between the phased array antenna control system and the individual phase control module and radiator assemblies forming the array must necessarily have an extremely complex construction, resulting in increased antenna manufacturing costs. In addition, this flow path which consists of discrete printed wiring board circuit layers and pin/socket or terminal/jumper wire connections forms an essentially hard-wired link between the antenna control system and the modules in the array. The detection of circuit faults or improper electrical connections in any hard-wired system requires a substantial amount of maintenance down time which, in this case, would result in an undesired shut-down of the antenna.
Therefore, there is a need for an improved assembly for use in a phased array antenna operable to provide a communication link between the control system of the antenna and the individual phase control module and radiator assemblies forming the antenna array. The improved assembly must provide an optic communication link to eliminate the problems associated with presently utilized hard-wired communication systems. The improved assembly must be of simple construction, and lend itself to easy maintenance and repair. In addition, there is a need for an improved phase control module and radiator assembly which may be used with the optic communication assembly of the present invention.